Recently, with the improvement of living standards, people have paid more and more attention to recreational activities in order to relieve work pressure. Barbecues, for example, are immensely popular and can be enjoyed by family members and friends of all ages. This is especially true in the United States and Europe, where spacious yards are so common that barbecues have become basic family activities, serving both recreational and social purposes, and where therefore great emphasis is placed on the features of the roasting equipment required.
Referring to FIG. 1, a commercially available rotisserie P60 is provided with a burner P61 having a generally square U-shaped cross section. The burner P61 defines a receiving space P611 therein for receiving roasting utensils and related materials such as a grill rack, a gas stove, or charcoal (not shown). The burner P61 has two opposite sidewalls provided with two fixing frames P62 and P63 respectively. The fixing frame P63 can be mounted with a motor assembly P64. The motor assembly P64 has a lateral side provided with a rotating shaft hole P642. The motor assembly P64 is also provided therein with a motor (not shown), which obtains the electric power required for normal operation through a power cord P643 in order to rotate a rotating shaft (not shown). The rotating shaft hole P642 corresponds to the rotating shaft and can be fitted with a spit P70. The spit P70 has one end to be connected with the rotating shaft and the other end to be placed in a recess P624 of the fixing frame P62. The spit P70 is further provided with a pair of prongs P651 at an appropriate position. The spit P70 and the prongs P651 can be pushed through the food P80 to be roasted (e.g., the whole chicken shown in the drawing) so that, with the motor assembly P64 driving the spit P70 into rotation, the food P80 is rotated over and heated by the gas-fueled fire or charcoal in the burner P61.
While a barbecue is in most cases held where there is mains electricity (e.g., in a backyard or on a campsite where electricity is available through an extension cord), it may also take place in the wild (e.g., during travel). In the latter case, however, the motor assembly P64 becomes useless due to the lack of mains electricity. As a solution, motor assemblies configured to be powered by batteries (e.g., alkaline D batteries) were developed, but the capacities of common batteries are so limited that one who wishes to barbecue while traveling must carry multiple spare batteries with them in order to drive such a motor assembly throughout the entire roasting process. The spare batteries are nevertheless bulky, taking up a lot of space and therefore adding to the inconvenience of travel.
The issue to be addressed by the present invention is to design a motor assembly that is applicable to a rotisserie and can be driven by various DC power sources (e.g., mobile power packs and batteries) so that one can roast food in the wild, or anywhere without mains electricity or the required battery, by driving the motor assembly with the mobile power pack on hand, wherein the mobile power pack is generally compact in size and is carried by the user with the original intention to charge a mobile communication device.